Abstract
Histologic assessment of response to progestogen therapy is a cornerstone of nonsurgical management of atypical hyperplasia/low-grade endometrioid carcinoma. Pathologists are required to assess whether there is ongoing preneoplastic or neoplastic change in the biopsies (often multiple) taken during therapy. There have been few studies documenting the specific histologic changes induced by therapeutic progestogens and currently there are no guidelines on terminology used in this scenario. Given the need for uniformity in reporting and the lack of guidance in the current literature, we initiated an online survey (including questions, categories of reporting, and scanned slides for assessment) which was sent to all members of British Association of Gynaecological Pathologists (BAGP) and the International Society of Gynecological Pathologists (ISGyP) with the aim to assess the variability among pathologists in reporting these specimens and to come up with a consensus-based terminology for reporting of endometrial biopsies from women on progestogen therapy for endometrial atypical hyperplasia/endometrioid carcinoma. In total, 95 pathologists participated in this survey. This manuscript elaborates on the results of the survey with recommendations aimed at promoting uniform terminology in reporting these biopsies.